Display screen or portion thereof with transitional graphical user interface



FIG. 1 is the first image in a sequence for a display screen or portion thereof with transitional graphical user interface showing our new design;

FIG. 2 is a second image in a sequence thereof;

FIG. 3 is a third image in a sequence thereof;

FIG. 4 is a fourth image in a sequence thereof; and,

FIG. 5 is a fifth image in a sequence thereof.

The outer-most broken line showing of the display screen, and the broken line showing of portions of the transitional graphical user interface, are for the purpose of illustrating portions of the article and form no part of the claimed design.

The appearance of the transitional graphical user interface sequentially transitions between the images shown in FIGS. 1 through 5. The process or period in which one image transitions to another forms no part of the claimed design.

The darker, bolder lines depicting text in the drawings represent a visual emphasis. 

CLAIM We claim the ornamental design for a display screen or portion thereof with transitional graphical user interface, as shown and described. 